The market is somewhat above its historic levels relative to trend earnings. Pearlstein cites Shiller who puts the price to earnings ratio at 25 to 1, compared to a historic average of 16. ... I would agree that stock prices are somewhat above trend, but not by quite as large a margin as Shiller.

To get some perspective, at the peak of the stock bubble in early 2000, the S&P peaked at just under 1530. The economy is almost than 70 percent larger today (in nominal dollars), which would mean that the S&P would be over 2600 today if it were as high relative to the economy. If we throw in that the economy is still operating at 5 percent below its potential then the S&P would have to be over 2700 now to be as high relative to the economy as it was at the peak of the stock bubble. With a Friday close of 1863, we can see the market is at a level that is a bit more than two thirds of its 2000 bubble peak, relative to the size of the economy.

It also is much lower relative to the economy than it was in 2007 when almost no one was talking about a stock bubble. The S&P peaked at just over 1560 in the fall of 2007. Taking into account the economy's 18 percent nominal growth over this period, and the fact that we are still 5 percent below potential GDP, the S&P would have to be over 1900 today to be as high relative to potential GDP as it was in 2007. Given recent patterns, it certainly doesn't make sense to talk about a bubble for the market as a whole.

However, there are some points worth noting. The social media craze has allowed many companies with no profits and few prospects for making profits to market valuations in the hundreds of millions or even billions of dollars. That sure looks like the Internet bubble. Some of these companies may end up being profitable and worth something like their current share price. The vast majority probably will not.

The other point is that the higher than trend price to earnings ratio means that we should expect to see lower than trend real returns going forward. This is an important qualification to Ritholtz's analysis. While there is no reason that people should fear that stocks in general will take a tumble, as they did in 2000-2002, they also would be nuts to expect the same real returns going forward as they saw in the past.

With a price to earnings ratio that is roughly one-third about the long-term trend, they should expect real returns that are roughly one-third lower than the historic average. This means that instead of expecting real returns on stock of 7.0 percent, they should expect something closer to 5.0 percent. That might still make stocks a good investment, especially in the low interest rate environment we see today, but probably not as good as many people are banking on.

In short, there is not much basis for Pearlstein's bubble story, but we should also expect that because of higher than trend PE ratios stocks will not provide the same returns in the future as they did in the past. Anyone who thinks we can better have their calculator checked.

The market is somewhat above its historic levels relative to trend earnings. Pearlstein cites Shiller who puts the price to earnings ratio at 25 to 1, compared to a historic average of 16. ... I would agree that stock prices are somewhat above trend, but not by quite as large a margin as Shiller.

To get some perspective, at the peak of the stock bubble in early 2000, the S&P peaked at just under 1530. The economy is almost than 70 percent larger today (in nominal dollars), which would mean that the S&P would be over 2600 today if it were as high relative to the economy. If we throw in that the economy is still operating at 5 percent below its potential then the S&P would have to be over 2700 now to be as high relative to the economy as it was at the peak of the stock bubble. With a Friday close of 1863, we can see the market is at a level that is a bit more than two thirds of its 2000 bubble peak, relative to the size of the economy.

It also is much lower relative to the economy than it was in 2007 when almost no one was talking about a stock bubble. The S&P peaked at just over 1560 in the fall of 2007. Taking into account the economy's 18 percent nominal growth over this period, and the fact that we are still 5 percent below potential GDP, the S&P would have to be over 1900 today to be as high relative to potential GDP as it was in 2007. Given recent patterns, it certainly doesn't make sense to talk about a bubble for the market as a whole.

However, there are some points worth noting. The social media craze has allowed many companies with no profits and few prospects for making profits to market valuations in the hundreds of millions or even billions of dollars. That sure looks like the Internet bubble. Some of these companies may end up being profitable and worth something like their current share price. The vast majority probably will not.

The other point is that the higher than trend price to earnings ratio means that we should expect to see lower than trend real returns going forward. This is an important qualification to Ritholtz's analysis. While there is no reason that people should fear that stocks in general will take a tumble, as they did in 2000-2002, they also would be nuts to expect the same real returns going forward as they saw in the past.

With a price to earnings ratio that is roughly one-third about the long-term trend, they should expect real returns that are roughly one-third lower than the historic average. This means that instead of expecting real returns on stock of 7.0 percent, they should expect something closer to 5.0 percent. That might still make stocks a good investment, especially in the low interest rate environment we see today, but probably not as good as many people are banking on.

In short, there is not much basis for Pearlstein's bubble story, but we should also expect that because of higher than trend PE ratios stocks will not provide the same returns in the future as they did in the past. Anyone who thinks we can better have their calculator checked.